Sequence control mechanism



Jan. 29,1952

R 6. SMITH SEQUENCE CONTROL MECHANISM Filed Feb. 5, 1948 Rifihurd C. Smiih IN V EN TOR.

HIS ATE-INT ATTORNEY Patented Jan. 29,- 1952 Richard C. Smith, Snyder, N. Y., assignor to Curtiss-Wright Corporation, a corporation .0!

Delaware Application February 5, 191:8, Serial No. 6497 4 Claims.

1 The present invention relates generally to con.- trol mechanisms and more particularly to improved arrangements and mechanisms for the selective control of a plurality of instrumentalities in a defiinite sequence of operation.

In the design of many machines and mechanisms, it is often desirable or even mandatory that provision be made for automatically operating elements ofthe machine or mechanisms from a single set of manual or other controls in a predetermined or desired sequence. Such requirements exist in aircraft engine installations of the reaction jet type in which it is necessary to initially open the high pressure iuel supply to the engine before the engine can he run and controlled by the throttle. Conversely, in order toshut on such an engine, it is necesary to first 'retardthe throttle and then to shut oi! the hi h pressure fuel source. In view of the numerous controls and instruments which :it is necessary that the pilot of :an aircraftcperate and examine at :frequent intervals. it is desirable that .both the fuel shut-offvalve andthe engine throttle be controlled from a single-actuating member, accessible to the pilot or operator. The present invention is directed to an improved device for accomplishing the desired sequence of operation in. connection with engine and similar installations. In :such installations, is is also advantageous, particularly in the operation :of aircraft, that the mechanism for accomplishing these sequence operations be made .as simple and foolproof as possible, and that they preferably be operated by asinglemanual controlmeans. It is also desirable that such mechanisms be -auto matic in theiroperation and provide for irreversible action .inorder to prevent disturbance of the positionto which theseveral devices may havebeen adjusted.

It is, accordingly,.a primary object of this in-.

vention to provide an improved mechanism .by which a series of sequential operations can .be accomplished from a single actuatingmeans. It is aiurther object to provide a mechanism of the Ioregoingcharacter in which a predetermined range and travel can .be-obtained in the desired sequence. It is another-object toprovideasimple, .positiveactingand ioolproofcmean'sior operatin automatically, and in the proper sequence, a plurality or devices .in the prescribed manner. Afiurther ,objectwresi'des' .in the-provision of a sequence mechanism having overriding andlostmotion means of a unitary construction which is adapted to be readily attached or connected to a controlsystem having thepresent requirements or sequential operation;

2 A still further object of the present invention resides in the provision of a unitary overriding and sequence mechanism which is automatically and positively locked in certain of its positions to provide irreversibility oi the connected operating mechanism and the devices which are operated thereby. It is another objective to provide mechanism of the type described provided with guide-slots and notches having improved contours and relationships by which back-pressure on the mechanism cannot eiiect a displacement of any of its parts. It is a still further object to provide an improved mechanism for the overriding and sequential control of the high pressure fuel source and control throttle of an "aircraft engine installation of the reaction jet type.

Other objects and advantages of the present invention will occur to those skilled in the art after a reading of the present description taken together with the accompanying drawings, forming a part hereof. in which Figure 1 is a perspective view of the sequence actuating mechanism;

Figure 2 is a cross-sectional diagrammatic view 25 of the mechanism of Figure 1, with the controlled devices in the retarded or off" position;

Figure 3 is a imilar diagrammatic view of the mechanism in its intermediate or mid-position; and

Figure 4 is a similar view showing the mechanism in its extended or full on operating position.

Referring now to Figure 1, it will be noted that the sequence mechanism is mounted upon a base assembly 5 to which are attached the vertical fixed supports 6 and to. These fixed supports 6 and 6a are laterally spaced apart and have disposed therebetweenva pair of bell-crank members 1 and la which are pivotally mounted (upon the fixed support at the pivot 8. The bell-cranks I and 1a are actuated by a control push-pull member ,9 .to which it is pivotally joined by-the pivot rod ill. The bell-crank members 1 and 1a,, in cooperation withthe supp rt members 6 and 6a, in turn actuate the controlled push-pull links H and [2, by virtue of their respective pivotal rollers l3 and 14, which are common to both the support plates 6 and 6a and the bell-cranks I and la as the result of these pivotal rollers vextending through arcuate slots in these support plates, which slots will be more fully described below. For the purposes of the present description, it will be understood that the push-pull link orrod ii is operatively connected to a shutoff valve for a high pressure iuelsource and the push pull'link or rod I2 is similarly operatively I5a, respectively, provided at their forward or right hand ends, as viewed in the accompanying drawings, with downwardly directed notches I8 and I8a; the upper slots in-these support members being 22 and 2212, which are provided at their rearward or left ends with downwardly directed notches I9 and I9a. Thebell-crank mom-.- hers I and la are also provided with corresponding lower and upper sets of arcuate guide slots Each of these arcuate slotsrearmost bell-crank member I and the vertical support member 6 only, it will be noted that the bell-crank I is in its rearward or off position in which the axis of the pivot Iil'is disposed to the left of the axis of the bell-crank 8; and the roller'pivots I3 and M are each'disposed at the forward ends of the movable bell-crank slots and atthe rearward ends of the fixed slots in the supporting member 6. It will be understood that, with the control member 9 in its retracted or leftmost position of Figure 2, the fuel valve operatively connected to the link II will be in its off or closed position, as will also be the engine throttle operatively connected to the link I2; 1

Letus assume now that the control member 9 is pushed forward or to the right into the positionshown in Figure 3, in which the axis of the pivot I is disposed substantially vertically above the axis of the bell crank pivot 8. It will be seen that the cooperative action of the slots I and H has caused the pivot roller I3 connected to the link II to be moved forward-"or to the right into a position in which the pivot I3 is also dispo'sed substantially above the pivot axis 8; and the link II has been moved toward the right to "thereby open the high pressure fuel valve to which this link is connected. This forward movement of the pivot I3 is caused by the cooperative action of the notch It at the forward'end of the bellcrank slot I! which serves to push the link I forward as the bell-crank is moved forwardly, or rotated in the clockwise direction about its pivot 8, the pivot I3 moving along the forwardly opened fixed slot I5 until it reaches the en thereof, above the adjoining notch I8.

In the meantime, it will be noted that the pivot I4, to which the link l2 forthe engine throttle is connected, has remained in its initial position in which it was vertically disposed above the bell-crank pivot B and accordingly the engine throttle has not been actuated during this initial half phase of the operation of the mechanism. This is due to theinitial position of the pivot It at the end of the slot in the bellcrank I being retained within the notch I9 of the slot-22 in the support 6, while the bell-crank .l and its slot 20 are moved or rotated forwardly into the position shown in Figure 3. This discrimination of the bell-crank 7, in moving the pivot I3 forward while permitting the pivot I4 to remain in its initial position, is due to the location of the notches I6 and I8 being at the forward ends of their respective slots I1 and I5, whereasin the case of-the'pivotv'l l, the-notches I9 and 2 I aredisposed 'at the rearward terminals of the slots 22 and 20, respectively. Due to the notch I6 in the bell-crank I engaging the pivot I3, the latter moves with the bell-crank during its initialhalf of the movement, and also for the reason that thenotch I9 of the fixed support engages the upper pivot I4, the latter is retained by the fixed support and the bell-crank with its slot 20 is permitted to be moved past the relatively fixed upper pivot I4, thereby preventing movement of the link x I2 and its associated throttle. Thus in the first half of the forward movement of the control rod 9,- the fuel valve associated-with the link ;II is -opened,-while the throttle connected to the link I2 is maintained in its initially closed position.

Referring now to Figures 3 and 4, let us assume that the forward movement of the control rod Bis continued from its mid-position, shown in Figure 3, to its fully extended or forward position shown in Figure'4; 'In the mid-positionshown in Figure 3, it will be seen that thecooperating slots I5 and H for the lower pivot I3 are adjacent to'or co-extensive with each other, with their respective not'ches' I8 and IS, in engagement with the pin I3, disposed at the forward terminals of the respectiveslots. On the other hand, while the upper pivot I4 is also engaged by the notches 2| i and I9, of the respective slots"2Il and 22 of the 'bell-crank'and the fixed structure respectively, these'no'tches' are disposed at the rearward or trailing ends of the slots. It will also be noted that the lower pivot I3 has the bell-crank slot I'I'disposed behind or to the left offthe pivot into which it maybe guided without concurrent'movement'of the bellcrank, and the upper pivot I4 is at the rearmost end of the bell-crank slot 20 substantially within the slot 2| with which it will be compelled to move forwardly upon further rotation of the bell-crank. Accordingly, as the bell-crank is rotated in the clockwise direction from its midposition of Figure 3 to the full or extended position of Figure 4, the pivot I3 is lowered slightly into the notch I8 of the fixed support Ii at which position the arcuate slot IT in the bell-crank "is permitted to pass over the pivot I3 withoutimparting forward movement thereto. Each pair of notches I 6 and I8, and I9 and 2|, exert a camming action to lower and lift the correspond ing pivots I3 and I4, respectively as forward movement is continued past the mid-position.

- ready been passed by during the initial movement of the bell-crank I and its slot 2|],v such that this pivot is now engaged by both notches I9 and 2| at its rearward end. Accordingly, as the bell-crank is rotated beyond its mid-position, these two notches cooperate to lift the pivot I4 upwardly into the end of thernotch 2| and into the arcuate path of the fixed slot 22 through which it is moved concurrently with continued forward movement of the control member 9 and the further rotation of the bell-crank I.

Accordingly during the last half of the movement of the control member 9, the link II, through the relatively fixedposition of its con': nected pivot I3 is maintained in its position keepat'cfgoss mg its associated --fuel valve open, whereas the upper pivot l4 associated *with the link-ll is moved forwardly causing the link i2 to adjust thethrottle into its open position; -The-'re'lative movements of the associated elements in the present mechanism may be more particularly understood by noting that in the starting position in Figure 2 inwhich bothi tlie'fuel' valve and the'throttle are'in the off position, the pivots merit of the. upper pivot 14 concurrently-with the controlmemberpivotl0, the pivots 8 and t3zremain in substantial vertical. alignment whenthe full or extended position is .reached, while the pivots H), 1.4 and I3 are. in substantial alignment along. an upwardly sloping line ltowardtthe. right as shown in Figure 4.

It will, accordingly, be noted that the presently described mechanism permits the selective operation of two controlled devices or instrumentalities causing the selective operation of one of these devices, while permitting the overriding of the other during the first half of the operation of the mechanism; and causing the overriding of the initial device during the second half of the opera tion, while causing selective actuation of the second controlled device. It will be apparent to those skilled in the art that as the control member 9 is returned from its full position of Figured to the mid-position of Figure 3, the pivot l4 and the associated link 12 connected to the throttle will serve to close the throttle while at the same time the fuel valve associated with the pivot l3 and the link I i will be maintained in its open position. As the control member 9 is further withdrawn to its initial or starting position, as shown in Figure 2, it will be seen that, while no further movement is imparted to the pivot 14, the link -i 2 and the associated throttle, the lower pivot I3.- is withdrawn rearwardly with the bell-crank 1, imparting movement to the connected link H and serving to close the fuel valve associated therewith. Accordingly, as the mechanism is returned from its full position to its initial starting posi; tion, the controlled devices are actuated in the reverse order of the forward movement of the mechanism thereby insuring positive and fool proof actuation of the fuel valve and engine throttle.

As indicated above, the present mechanism is not limited to use with the specific instrumentalities which have been described herein, but has general application and is capable of advantageous and satisfactory results in other installations, which are required to be operated in accordance with a predetermined sequence and overriding characteristics. Other forms and modifications of this invention, both with respect to the general arrangement and the details of its respective elements, which occur to those skilled in the art after reading the present description, are intended to come within the scope and spirit of the present invention as more particularly defined in the appended claims.

' 1. In a sequence operatin'g deviceofithetype described, "a relatively 'fixedsupporting member having-a plurality of curvedslots, -a' movable memberpivotahy mounted-at a fixed pivot carried by'said supporting member forcontiguous movements with: respect to saidfixed supporting member, said movable member having a-plur'ality of curved'slots open to'corresponding 'contiguous slots of said fixed member, one pair 0: said corresponding slots comprising-a-slot in said fixed member and'a slot in said movable member being spaced radially from said fixed "pivot a greater distance-thanthe other said pair of' 'corresponding slots, a I plurality of controlled members each having a pivotal portion slidablyengaging one of the 'pairs-ofcontiguous curved slots of' said' movable and said fixed members, and-difset portions in each of said pairs 'of curved slots arranged to provide a predeterminedsequence'of movement selectively "transmitted 'to said controlled members upon movementof said-movable member as determined by' therelative positions ofthe offset portionsof the .curveds'lots o'fsaid fixedand movablemembers.

2. An .overridingand sequence mechanism for the operation of 1 a"fuel supply' valve "and; throttle comprising a support member, "a pair of guide slots formed within said support member, a movable member pivotally mounted upon a fixed pivot carried by said support member for movements with respect thereto, said pair of guide slots being radially spaced from said fixed pivot, a second pair of similarly radially spaced guide slots formed within said movable member, the more distantly spaced slots in said support and movable members forming a first set of adjacent guide slots, the more closely spaced slots in said support and movable members forming a second set of adjacent guide slots, a follower element connected to a fuel valve engaging the first set of said adjacent guide slots in said support and movable members, a follower element connected to a throttle engaging the second set of said adjacent guide slots in said support and movable mem-- bers, actuating means for imparting pivotal movements to said movable member about its said fixed pivot and offset terminal portions in said guide slots arranged in radial alignment with respect to said fixed pivot for the simultaneous radial shifting of both said follower elements whereby initial opening of said fuel supply valve and the subsequent opening of the throttle is accomplished while further opening of said fuel valve is prevented by overriding of said mechanism.

3. In an overriding and sequence mechanism for the operation of a fuel supply valve and throttle including a support member, a pair of guide slots associated with said support member, a movable member pivotally mounted upon a fixed pivot carried by said support member for pivotal movements with respect thereto, said guide slots "radially spaced from said fixed pivot, a pair of similarly radially spaced guide slots associated with said movable member, the more remotely spaced slots in said support and movable members forming a first set of adjacent guide slots,

the more closely spaced slots in said support and nected to a throttle engaging the second set of said adjacent guide slots in said support member and said movable member and actuating means for imparting movements to said movable member about its said fixed pivot, the improvement wherein ofiset terminal portions in said guide slots are arranged in radial alignment with respect to said fixed pivot for the simultaneous radial shifting of both said follower elements at the end of the first stage of movement of said actuating means during which said fuel supply valve only is opened and prior to the start of the second stage of said movement wherein the throttle only is operated and further opening of said fuel valve is prevented-by overriding of said mechanism, 7 p p 4. In a sequence operating device of the type described, a relatively fixed supporting member having first and second curved slots, a movable member pivotally mounted upon a fixed pivot carried by said supporting member for contiguous movements with respect to said fixed supporting member, said movable member having corresponding first and second curved slots open to and contiguous to the respective first and second 5 slots of saidfixed member. the first slots. of said fixed and movable members being spaced radially from said fixed pivot a greater distance than the sequence of movement selectively transmitted to said controlled members upon movement of said movable member as determined by the relative positions of theofiset portions of the curved slots of said fixed and movable members.

RICHARD C. SlVHTH.

' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 245,045 Baker Aug. 2, 1881 621,193 Wilson Mar. 14, 1899 691,9685 Paine Jan. 28, 1902 1,667,842 -Coykendall May 1, 1928 1,985,014 Bush Dec. 18, 1934 2,199,095 Banker Apr. 30. 1940 

